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Biomedical subjects

M Sheaff

Publications and source records attributed to M Sheaff.

At least 19 recordsLinked to original sources
PubMed2003

Angiosarcoma of the breast: a 30 year perspective with an optimistic outlook.

The aim of this study was to investigate the incidence and clinicopathological features of angiosarcoma of the breast by focusing on those cases passing through a busy general teaching hospital over a 30 year period. A search was carried out of all cases in the files of the Department of Pathology of the Royal London Hospital from 1970 to 2000. Four cases were identified as primary angiosarcomas involving the breast. The medical and surgical histories, macroscopic and microscopic features and clinical outcome with long-term follow-up are described in each case. Similarities were identified, such as initial presentation with a 'bruise' and a latent period before the diagnosis was established. Half of our cases followed irradiation for breast cancer. In all cases the prognosis after surgery was excellent. The rarity of primary mammary angiosarcoma was confirmed. In younger patients the lesion was not associated with previous radiotherapy, but the older patients presented after radiotherapy for adenocarcinoma of the breast. Although very uncommon, these tumours must be considered in the differential diagnosis, especially with the increasing use of fine-needle-aspiration and core biopsy for preoperative diagnosis. The prognosis after complete surgical excision may be better than generally believed.

Adult↗
PubMed2002

Dalitz plot analysis of the decay D(+)-->K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance.

We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Journal Article↗
PubMed2002

Search for CP violation in the decays D+--> K(S)pi+ and D+-->K(S)K+.

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D+-->K(S)pi+ and D+-->K(S)K+. We have measured the following asymmetry parameters relative to D+-->K-pi+pi+: A(CP)(K(S)pi+) = (-1.6+/-1.5+/-0.9)%, A(CP)(K(S)K+) = (+6.9+/-6.0+/-1.5)%, and A(CP)(K(S)K+) = (+7.1+/-6.1+/-1.2)% relative to D+-->K(S)pi+. We have also measured the relative branching ratios and found Gamma(D+-->K(0)pi+)/Gamma(D+-->K-pi+pi+) = (30.60+/-0.46+/-0.32)%, Gamma(D+-->K(0)K+)/Gamma(D+-->K-pi+pi+) = (6.04+/-0.35+/-0.30)%, and Gamma(D+-->K(0)K+)/Gamma(D+-->K(0)pi+) = (19.96+/-1.19+/-0.96)%.

Journal Article↗
PubMed2001

Secondary neoplasms of the breast: a survey of the 20th Century.

BACKGROUND: A 90-year archive of surgical and postmortem material was reviewed to establish the incidence, presentation, and pathology of tumors secondary to the breast. METHODS: A search was performed on all cases contained within the files of the Pathology Department of the Royal London Hospital from 1907 to 1999. RESULTS: Sixty patients were identified with unequivocal, secondary, nonmammary neoplasms involving the breast. Hematologic tumors predominated, particularly among the more recent cases, with carcinoma less frequent overall but more numerous in the earlier part of the 20th century. There were several surprising and sometimes unique findings, with occasional metastases from primary tumors of the esophagus, retina, pancreas, thyroid, and skin. Other primary tumor sites included the stomach, lungs, and kidney. In line with expectations, the majority of tumors occurred in women. CONCLUSIONS: Secondary tumors to the breast are rare. In the current series, these tumors comprised 3% of the breast tumors in the files under review. The majority of these were metastases from the contralateral breast. However, the existence of metastatic nonmammary tumors to the breast should be appreciated so that secondary tumors from unusual sites are not overlooked, particularly with the widespread use of fine-needle aspiration cytology and needle core biopsies for preoperative diagnosis. In fact, 0.43% of the breast malignancies in the current report originated from sites outside the breast. Of these one-third represented spread from an occult primary. Furthermore, the current data suggest a move from carcinomatous metastases to hematologic malignancies over the last century, possibly reflecting earlier diagnosis of the former and an increase in the prevalence of the latter.

Adolescent↗
PubMed2001

Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared.

We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets.

Journal Article↗
PubMed2001

Observation of color-transparency in diffractive dissociation of pions.

We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

Journal Article↗
PubMed2001

Search for rare and forbidden Charm Meson decays D0 --> Vl+l- and hhll.

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Journal Article↗
PubMed2001

Study of the D(+)(s)-->pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths.

From a sample of 848+/-44 D(+)(s)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)-->pi(-)pi(+)pi(+))/gamma(D(+)(s)-->straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Journal Article↗
PubMed2001

Experimental evidence for a light and broad scalar resonance in D(+) --> pi(-)pi(+)pi(+) decay.

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

Journal Article↗
PubMed2000

DNA copy number changes in Schistosoma-associated and non-Schistosoma-associated bladder cancer.

DNA copy number changes were investigated in 69 samples of schistosoma-associated (SA) and non-schistosoma-associated (NSA) squamous cell carcinoma (SCC) and transitional cell carcinoma (TCC) of the bladder by comparative genomic hybridization (CGH). DNA copy number changes were detected in 47 tumors. SA tumors had more changes than NSA tumors (mean, 7 vs. 4), whereas the number of changes in SCC and TCC tumors was similar. SA tumors displayed more gains than losses (1.7:1), whereas NSA tumors showed an equal number of gains and losses. Changes that were observed at similar frequencies in SCC and TCC, irrespective of the schistosomal status, included gains and high-level amplifications at 1q, 8q, and 20q and losses in 9p and 13q. These changes may be involved in a common pathway for bladder tumor development and progression independent of schistosomal status or histological subtype. Losses in 3p and gains at 5p were seen only in SCC (P < 0.01) and losses in 5q were more frequent in SA-SCC than in other tumors (P < 0.05). However, changes that were more frequent in TCC than those in SCC included gains at 17q (P < 0.01) and losses in 4q (P < 0.05) and 6q (P < 0.01). Gains and high-level amplifications at 5p were seen only in SA-SCC (P < 0. 01), whereas gains and high-level amplifications with minimal common overlapping regions at 11q13 were more frequently seen both in SA-SCC and SA-TCC tumors (P < 0.01). In addition to the above mentioned alterations, several other changes were also seen at lower frequencies. The variations in the DNA copy number changes observed in TCC, SCC, SA, and NSA bladder carcinomas suggest that these tumors have different genetic pathways.

Aged↗
PubMed2000

Membranous nephropathy resolving with treatment of bronchial carcinoid tumor.

The nephrotic syndrome and membranous nephropathy is well recognized in association with solid tumors, although less is understood of the process that links them. We report a 27-year-old man presenting with the nephrotic syndrome and stage I membranous glomerulonephritis on biopsy. A bilar mass with regional lymphadenopathy was found simultaneously, the histology of which was shown to be an infiltrative atypical bronchial carcinoid tumor. The neoplasm was successfully treated with combined chemotherapy and radiotherapy, and over this period his nephrotic-range proteinuria resolved. As has been described with other malignancies, membranous nephropathy associated with a bronchial carcinoid tumor may resolve with treatment of the underlying condition.

Adult↗
PubMed2000

CMV colitis in early HIV infection.

Cytomegalovirus (CMV) colitis is a well recognized complication of advanced HIV disease and is only rarely diagnosed in patients with normal immune function. A case of CMV colitis occurring in early HIV infection is described. Although CMV infection is normally confined to patients with advanced HIV disease, it is possible that a number of contributing factors may have led to clinical disease in this patient. CMV colitis is an important diagnosis to consider in all patients who present with a diarrhoeal illness associated with systemic features, regardless of underlying immunosuppression.

Adult↗
PubMed1998

Appendiceal inflammation in ulcerative colitis.

AIMS: Previous uncontrolled reports have suggested that appendiceal inflammation may occur as a discontinuous lesion in ulcerative colitis. This study aims semiquantitatively to compare the prevalence and histological features of appendiceal inflammation in patients with ulcerative colitis and Crohn's disease, using colonic carcinoma and acute appendicitis specimens as controls. METHODS AND RESULTS: Surgical pathology records and original histological slides for the period 1980-1994 were examined. The prevalence of appendiceal inflammation in ulcerative colitis (24/50, 48%), was higher than in colonic carcinoma (5/65, 8%, P < 0.001), but was similar to that in Crohn's disease (14/27, 52%). Appendiceal inflammation with caecal sparing was seen in nine out of 24 specimens with ulcerative colitis (37%), two out of nine (22%) with Crohn's disease and five out of 65 (8%) with colonic carcinoma. Inflamed appendixes from patients with inflammatory bowel disease showed histological features typical of ulcerative colitis and Crohn's disease rather than acute appendicitis and were significantly less likely to have transmural inflammation. There had been a previous appendicectomy in 3% of ulcerative colitis patients compared with 8% of colonic carcinoma specimens and 21% (P < 0.01) Crohn's disease controls. CONCLUSION: In ulcerative colitis, as in Crohn's disease, appendiceal inflammation commonly occurs as a skip lesion and histologically resembles the colonic disease rather than acute appendicitis. The low prevalence of appendicectomy supports the hypothesis that the appendix itself may have a central role in the pathogenesis of ulcerative colitis.

Adolescent↗
PubMed1997

Primitive neuroectodermal tumor of the kidney confirmed by fluorescence in situ hybridization.

Peripheral primitive neuroectodermal tumors (PNETs) are rare lesions that form part of the Ewing family of tumors, which includes osseous and extraosseous Ewing's sarcoma and Askins tumor of the thorax. All are characterized by translocations involving the EWS gene at 22q12, usually the translocation t(11;22)(q24;12). PNETs usually occur in soft tissues but occasionally arise within a visceral organ. We describe a PNET of the kidney that showed characteristic microscopic and immunohistochemical appearances of a small, round, dark blue cell tumor with focal rosette formation and strong membrane positivity for the MIC2 gene product. Interphase fluorescence in situ hybridization on touch imprints prepared from frozen tissue using cosmid probes flanking the EWS gene at 22q12 and the FLI1 gene at 11q24 indicated the presence of t(11; = +22)(q24; = +q12), confirming the diagnosis of PNET. This is the first reported PNET of the kidney supported by cytogenetic analysis. We also review the literature on this fascinating tumor in this unusual location.

Female↗